High-accuracy contactless measurement method for measuring temperature of metal thermoforming mold

Abstract

The present invention aims at providing a high-accuracy contactless measurement method for measuring the temperature of a metal thermoforming mold, which is capable of timely monitoring the metal temperature in multiple areas and also has threshold warning functionalities for delivering real-time notifications, in order to save the labor costs for long-term monitoring.

What is claimed is: 
     
       1. A high-accuracy contactless measurement method for measuring a temperature of a metal thermoforming mold, the method comprising steps of:
 (A): spraying a high temperature resistant coating on a metal to be measured, wherein the high temperature resistant coating is in a visible band of an infrared band, for determining a monitoring area on the high temperature resistant coating; 
 (B): providing a temperature sensor, measuring a focal plane array (FPA) of the temperature sensor, obtaining an FPA operating temperature, determining a thermal radiation calibration regression coefficient based on the FPA operating temperature, and calibrating the temperature measured by the temperature sensor based on the thermal radiation calibration regression coefficient; 
 (C): providing a contact temperature sensor, measuring the high temperature resistant coating to obtain a contact temperature value by using the contact temperature sensor, measuring the high temperature resistant coating to obtain a contactless temperature value by using the temperature sensor, and calculating the contactless temperature value to compensate an error of the contactless temperature value with the contact temperature value so as to obtain a calculated temperature value by taking the contact temperature value as a basic value; 
 (D): setting a group of upper and lower limits of variations of the FPA operating temperature based on the FPA operating temperature, measuring the FPA to obtain a real-time FPA operating temperature and comparing the real-time FPA operating temperature with the FPA operating temperature obtained in Step (B), and returning to perform Step (B) to Step (D) when the real-time FPA operating temperature is greater than the upper limit of variations of the FPA operating temperature or smaller than the lower limit of variations of the FPA operating temperature; 
 (E): setting a group of upper and lower thresholds of temperature, analyzing the calculated temperature value of the high temperature resistant coating in the monitoring area, and showing a warning sign on a monitoring display when an average value of the calculated temperature values of all of the analyzable high temperature resistant coatings is greater than the upper threshold of temperature or smaller than the lower threshold of temperature. 
 
     
     
       2. The high-accuracy contactless measurement method for measuring a temperature of a metal thermoforming mold of  claim 1 , wherein Step (B) further comprises:
 measuring the temperature sensor and an environment to obtain a shell temperature and an environmental background temperature, and determining a plurality of thermal radiation calibration regression coefficients according to the environmental background temperature, the shell temperature and the FPA operating temperature. 
 
     
     
       3. The high-accuracy contactless measurement method for measuring a temperature of a metal thermoforming mold of  claim 2 , wherein the step of determining a plurality of thermal radiation calibration regression coefficients according to the environmental background temperature, the shell temperature and the FPA operating temperature comprises:
 looking up a calibration regression coefficient table to read the plurality of thermal radiation calibration regression coefficients corresponding to the environmental background temperature, the shell temperature and the FPA operating temperature; 
 wherein the calibration regression coefficient table is related to a calculation result obtained when electronic signals generated by the temperature sensor measuring objects having different temperatures and at least one thermal radiation calibration regression coefficient among the plurality of thermal radiation calibration regression coefficients are fixed values. 
 
     
     
       4. The high-accuracy contactless measurement method for measuring a temperature of a metal thermoforming mold of  claim 1 , wherein materials of the high temperature resistant coating comprise a pigment, a resin and an organic solvent. 
     
     
       5. The high-accuracy contactless measurement method for measuring a temperature of a metal thermoforming mold of  claim 1 , wherein a difference between the calculated temperature value of the high temperature resistant coating and a real temperature value of the high temperature resistant coating is smaller than 1 degree Celsius. 
     
     
       6. The high-accuracy contactless measurement method for measuring a temperature of a metal thermoforming mold of  claim 1 , wherein the infrared band is a wavelength of 8-14 nm. 
     
     
       7. The high-accuracy contactless measurement method for measuring a temperature of a metal thermoforming mold of  claim 1 , wherein the temperature sensor is a sensor device based on a micrometric thermal radiation sensor.